By using the high resolution electron microscope (HREM), we observed the front of the newly formed crystals of the remineralized material. The whiskers of the apatite crystals were epitaxially aligned perpendicularly to the acid-etched enamel surface, and the crystal of the acid-etched surface enamel must be serving as the host crystals in epitaxy of the newly formed whiskers. These findings were confirmed with the computed images produced by multi-slice method. Effects of the various factors such as fluoride, mechanical brushing, aquired pellicle, or 1-hydroxyethylidene-1, 1-bisphosphonante (HEBP) on the remineralization process of the acid-etched enamel were also examined by applying these factors previously to the acid-etched enamel. HREM, TEM, scanning electron microscope (SEM), electron probe microanalyser (EPMA) and chemical analytical methods were used to evaluate the effects of these factors. For example, a fluoride releasing coating material (F-coat) was applied clinically to
… Morethe incipiently carious surface enamel of the primary teeth of the child patients, and EPMA observation of the surface enamel of the exfoliated primary teeth revealed the extent and amount of the fluoride taken up into the inner layer as well as outer layer of the specimen. HREM observation of the same specimen also revealed the arrangement of apatite crystals in the F-coat applied area of the specimen and it's image showed the stacking fault possibly caused by fusion of the crystals, suggesting that the demineralization of the surface enamel was taking place with support of the fluoride released from the F-coat in situ. The results of the study are providing the scientific evidence for the acid-etching technique in the adhesive dentistry and the significance of the fluoride releasing materials in everyday dental practice.例えば、フッ素徐放性コート材(F・コート材)を乳臼歯の所期齲蝕罹患歯面に診療室で塗布して、その乳臼歯が交換期に達して脱落するのを待って観察資料とし、F・コート材を塗布した歯面の再石灰化状態や、フッ素の歯面への取り込み状態をEPMAで観察した結果、in vitroで見られたものに類似したエナメル質中のフッ素の分布状態を明らかにすることができた。また同じ資料について、HREMによる観察を行ったところ、当該部にアパタイト結晶の配列が見られたばかりでなく、結晶の融合によると考えられる積層欠陥が見出された。再石灰化生成物質の超微構造に関する研究成果は、日常の歯科臨床で多用されている接着修復技術の前提となっている、歯質の酸処理法に科学的基盤を与えていると考えている。 Less